The purpose of this project is to characterize various immunogenetic parameters for use as markets in genetic, reproductive, and developmental studies on primates; specifically, to characterize the blood groups and allotypes of Rhesus monkeys (Mucaca mulatta). The controlled breeding program at the University of Wisconsin Regional Primate Research Center makes this colony uniquely suited for such studies. Since the mission of the Center is to obtain basic information in neurobehavior and reproduction, the immunogenetic parameters will be studied as to their relevance to these areas. We already have 17 reagents detecting 5 blood group systems of the rhesus monkey. They have been useful in establishing parentage, and in demonstrating transplacental isoimmunization. Our future objective is to broaden our program as follows: (1) Delineate more blood group and allotypic markers for linkage studies, correlations with other genetic factors and as monitors in bone marrow transplantation. (2) Investigate maternal-fetal incompatibility. Study the role of immunologic factors in fertility, fetal and neonatal death, and the immunoglobulins and lipoproteins and their role in reproduction and development. (4) Study the relationship of blood groups and allotypes to similar factors in humans, and to histocompatibility factors.